document.write(
    ` <div class="footer" >
        <a class="f-item" >
          <i class="iconfont icon-zixun"></i>
          <h3>咨询</h3>
        </a>
        <a class="f-item" onclick="fn()" >
          <i class="iconfont icon-yuyue"></i>
          <h3>预约</h3>
        </a>
      </div>

<div class="yuyue" >
      <div class="yuyue-main" >
        <h3>给我们留言</h3>
        <span>请填写以下信息，我们会尽快和您联系！</span>
        <div class="main-i" >
          姓名 <input type="text">
        </div>
        <div class="main-i" >
          电话 <input type="text">
        </div>
        <div class="main-i" >
          留言内容 <textarea></textarea>
        </div>

        <div class="btn" >
          <button  onclick="fn()">取消</button>
          <button  onclick="fn()">发送</button>
        </div>

      </div>
    </div>`
)

var footer = document.querySelectorAll('.f-item')
var yuyue = document.querySelector('.yuyue')

function fn(){
  yuyue.classList.toggle('yu')
}

